[Discuss-gnuradio] Need help with control port client

[Alexandru Csete]

Greetings,

I'm trying to write a control port client in C++ but I got stuck and
need some help.

My problem is that the control port interface gives us a map
containing GNURadio::KnobPtr but to get access to the value I need a
typed pointer, e.g. GNURadio::KnobDPtr, which is derived from KnobPtr.
I tried a static_cast as illustrated in this snippet:
http://pastebin.com/NqWyqSeu - but gcc throws it right back at me with
an error:

In file included from /usr/include/Ice/LocalObjectF.h:15:0,
                 from /usr/include/Ice/CommunicatorF.h:24,
                 from /usr/include/Ice/Initialize.h:13,
                 from /usr/include/Ice/Ice.h:13,
                 from strx-mon.cpp:1:
/usr/include/Ice/Handle.h: In constructor
‘IceInternal::Handle<T>::Handle(const IceInternal::Handle<Y>&) [with Y
= GNURadio::Knob, T = GNURadio::KnobD]’:
strx-mon.cpp:28:72:   instantiated from here
/usr/include/Ice/Handle.h:73:9: error: invalid conversion from
‘GNURadio::Knob*’ to ‘GNURadio::KnobD*’ [-fpermissive]

Maybe I'm approaching it all wrong. In any case, I would appreciate
any hints I can get.

Alex